when do a mummy cat's breasts go down?

My little princess had kittens just over ten weeks ago, and as she started losing interest we gave them to good homes. Thw last kitten went to their new family about three days ago, and she has stopped sort of leaking milk. I was wondering though, the areas under her nipples (milk glands?) Are still very full looking. Is this normal in your experience and when shoud they settle down?

It does take a while for the mammary glands to go back to normal.  Our shelter spay vet requires that all kittens be away from the mama cat for at least TWO WEEKS before they will spay them to avoid damaging the tissue.  For that reason, I would say that you can expect your cat's mammary tissue to be back to normal in about 11 days (two weeks minus 3 days).  At that time, you can safely take her to get spayed.  You can go ahead and make the appointment now, but don't make it sooner than about two weeks from now.  She may go back into heat at any moment so be sure to keep her inside until after she is spayed and recovered from surgery, usually another two weeks.

@Rotovia    I hope this answer is what you needed?

Good luck!